Disazo Compound

ABSTRACT

PCT No. PCT/GB95/01110 Sec. 371 Date Jan. 30, 1997 Sec. 102(e) Date Jan. 30, 1997 PCT Filed May 17, 1995 PCT Pub. No. WO95/31505 PCT Pub. Date Nov. 23, 1995A compound of the Formula (1) and salts thereof:    &lt;IMAGE&gt;  Formula (1)  wherein: A is optionally substituted phenyl or optionally substituted naphthyl; R1 is NR4R5; R2 is H, halo, -COOH, -SO20H, optionally substituted alkyl, optionally substituted alkoxy, or optionally substituted alkylthio; R3, R4 &amp; R5 are each independently H or optionally substituted alkyl; T is H or sulpho; and B is H, optionally substituted alkyl or optionally substituted phenyl; provided that the compound does not contain a piperazinyl group. The compound is suitable for use as a black colorant in ink jet printing inks especially for printing on plain paper.

This invention relates to a coloured disazo compound and aqueoussolutions thereof suitable for use in the coloration of substrates,especially sheet materials such as paper, and especially by a printingprocess such as ink jet printing.

According to a first aspect of the present invention there is provided acompound of the Formula (1) and salts thereof: ##STR2## wherein: A isoptionally substituted phenyl or optionally substituted naphthyl;

R¹ is NR⁴ R⁵ ;

R² is H, halo, --COOH, --SO₂ OH, optionally substituted alkyl,optionally substituted alkoxy, or optionally substituted alkylthio;

R³, R⁴ & R⁵ are each independently H or optionally substituted alkyl;

T is H or sulpho; and

B is H, optionally substituted alkyl or optionally substituted phenyl;

provided that the compound does not contain a piperazinyl group.

It is preferred that the compound of Formula (1) or (2) has at least asmany carboxy (--COOH) groups as sulpho (--SO₂ OH) groups, morepreferably not more than 2 sulpho groups and especially only a singlesulpho group. It is also preferred that the compound of Formula (1) or(2) has from 1 to 5, more preferably from 1 to 3, and especially 2 or 3carboxy groups.

When A is substituted it preferably carries from one to three,especially one or two, substituents selected from:

carboxy; sulpho; --OH; --CN; --NO₂ ; --PO(OH)₂ ; --B(OH)₂ ;

halo, preferably --Cl;

alkyl, preferably C₁₋₄ -alkyl and especially methyl;

alkoxy, preferably C₁₋₄ -alkoxy and especially methoxy;

--COOR³, wherein R³ is as hereinbefore defined other than H;

--SO₂ R⁶ or --COR⁶, wherein R⁶ is optionally substituted C₁₋₄ -alkyl oroptionally substituted aryl;

optionally substituted amino, preferably --NQ¹ wherein Q¹ and Q² areeach independently H or optionally substituted alkyl or aryl, or Q¹ andQ² , taken together with the N atom to which they are attached, form anoptionally substituted 5-, or 6-membered ring, especially an optionallysubstituted morpholine or piperidine ring; and

acylamino, especially alkyl- or aryl-carbonylamino or alkyl- oraryl-sulphonylamino, more especially C₁₋₄ -alkyl--CONH--or C₁₋₄-alkyl-SO₂ NH--.

It is, however, preferred that A does not contain a heterocyclicsubstituent.

It is especially preferred that A is carboxyphenyl or carboxynaphthyl,especially 3- or 4-carboxyphenyl group or carboxyphenyl having one ortwo further substituents, especially one, selected from carboxy, sulpho,methyl, methoxy and chloro. Examples of optionally substituted phenyland naphthyl groups represented by A are 4-carboxy-phenyl,3-carboxy-phenyl, 3,5-dicarboxy-phenyl, 3,4-dicarboxyphenyl,2-methyl-5-carboxy-phenyl, 2-methoxy-5-carboxyphenyl,2-chloro-5-carboxyphenyl, 3- and 4-amino-5-carboxyphenyl,2-sulpho-5-carboxy-phenyl, 4-carboxynaphth-1-yl, 5-carboxynaphth-1-yl,6-carboxy-naphth-1-yl, 7-carboxynaphth-1-yl, 6-carboxynaphth-2-yl and-sulpho-6-carboxynaphth-2-yl.

When R⁶, Q¹ or Q² is optionally substituted alkyl it is preferably C₁₋₄-alkyl, such as methyl, ethyl, propyl or butyl optionally carrying ahydroxy or amino group. When R⁶, Q¹ or Q² is optionally substituted arylit is preferably phenyl.

R² is preferably C₁₋₄ -alkyl, especially methyl or ethyl; C₁₋₄ -alkoxy,especially methoxy or ethoxy, C₁₋₄ -alkylthio, especially methylthio;Cl; H; COOH; or SO₂ OH. R³ is preferably H or C₁₋₄ -alkyl, morepreferably H, methyl or ethyl.

Where R⁴ or R⁵ is alkyl it is preferably C₁₋₄ -alkyl. Where one of R⁴and R⁵ is C₁₋₄ -alkyl, the other is preferably H, although it is furtherpreferred that both of R⁴ and R⁵ are H.

Where Q¹, Q², R², R³, R⁴, R⁵ or R⁶ is substituted alkyl or substitutedalkoxy, or Q¹ and Q² form a ring, the substituent(s) is preferablyselected from --COOH, --SO₂ OH, OH, NH₂, C₁₋₄ -alkoxy and halo,especially chloro. Where R⁶, Q¹ or Q₂ is substituted aryl it ispreferably phenyl and the substituent(s) is preferably in the 2-, 4-,2,4-, 3,4- and 3,5-position(s) and selected from --COOH; --SO₂ OH; OH;NH₂, CN; NO₂ ; C₁₋₄ -alkyl; C₁₋₄ -alkoxy; and halo, especially chloro.

The optionally substituted phenyl group represented by B may carry oneor more substituents selected from the same group as the optionalsubstituents on A, especially sulpho; carboxy; C₁₋₄ -alkyl; C₁₋₄-alkoxy; and chloro. The optionally substituted alkyl group representedby B is preferably C₁₋₄ -alkyl which may be unsubstituted or may carryone or more substituents selected from --SO₂ OH, OH, C₁₋₄ -alkoxy,amino, especially NH₂, and halo, and more especially, --COOH. It ispreferred that B is H, unsubstituted phenyl or C₁₋₄ -alkyl or phenylsubstituted by one or two carboxy groups and, optionally furthersubstituted by one or more substituents selected from those listed aboveas optional substituents or C₁₋₄ -alkyl substituted by amino orpiperidine.

Examples of preferred groups represented by B are 4-carboxy- phenyl,3-carboxyphenyl, 3,5-dicarboxyphenyl, 3,4-dicarboxyphenyl,2-methyl-5-carboxyphenyl, 2-methoxy-5-carboxyphenyl,2-chloro-5-carboxyphenyl, 2-sulpho-5-carboxyphenyl, phenyl, H, methyl,ethyl, propyl, butyl, carboxymethyl, 2-carboxyethyl and 2-aminoethyl.

Where B is free of carboxy groups it is preferred that A carries atleast one, and more preferably, two carboxy groups and where A is freeof carboxy groups it is preferred that B carries at least one, and morepreferably, two carboxy groups.

It is preferred that T is H.

A preferred compound of Formula (1) is where A is optionally substitutedcarboxyphenyl wherein any further substituent is selected from --COOH,--SO₂ OH, methyl, methoxy, chloro and hydroxy, especially 3- or4-carboxyphenyl or 3,4- or 3,5-dicarboxyphenyl; R² is H, methoxy ormethyl; R⁴ is H or C₁₋₄ -alkyl; R¹ is H, C₁₋₄ -alkyl, especially methylor ethyl; T and R³ are both H; and B is phenyl optionally having one ortwo carboxy substituents, especially phenyl, 3- or 4-carboxyphenyl or3,4- or 3,5-dicarboxyphenyl. An especially preferred compound is where Ais 3- or 4-carboxyphenyl or 3,4- or 3,5-dicarboxyphenyl; B is phenyl orselected from the groups represented by A; R² is H, methyl or methoxy;R⁵ is H, methyl, ethyl, acetyl or propionyl; and R³, R⁴ and T are H.

Another preferred compound of Formula (1) is where A is optionallysubstituted carboxyphenyl wherein any further substituent is selectedfrom --COOH, --SO₂ OH, methyl, methoxy, chloro and hydroxy, especially3- or 4-carboxyphenyl or 3,4- or 3,5-dicarboxyphenyl; R² is H, methoxyor methyl; R⁴ is H or C₁₋₄ -alkyl; R⁵ is H, C₁₋₄ -alkyl, especiallymethyl or ethyl; T and R³ are both H; and B is H or C₁₋₄ -alkyloptionally having one or two carboxy substituents, such as methyl,ethyl, carboxymethyl or 2-carboxyethyl. An especially preferred compoundis where A is 3- or 4-carboxyphenyl or 3,4- or 3,5-dicarboxy-phenyl; Bis H, methyl or ethyl; R² is H, methyl or methoxy; R⁵ is H, methyl,ethyl, acetyl or propionyl; and R³, R⁴ and T are H.

In the compound of Formula (1) it is preferred that the two azo groupsare in para (1,4) relationship across the central phenylene group andthat R¹ and R² are also in para (1,4) relationship across the centralphenylene group. It is also preferred that R¹ is ortho to the azo grouplinking A to the central phenylene group and that R² is ortho to the azogroup linking the Gamma acid moiety to the central phenylene group.

In the compound of Formula (1) it is preferred that all carboxy groupsare in positions which are not adjacent to groups with which they canform intramolecular hydrogen bonds, such as --NH², --NH-- and --OHgroups. Accordingly a preferred compound according to the invention isof Formula (2) or a salt thereof: ##STR3## wherein: G is3-carboxyphenyl, 4-carboxyphenyl, 3,4-dicarboxyphenyl,3,5-dicarboxyphenyl, or 2-methyl-5-carboxyphenyl;

J is H, methyl, ethyl, carboxymethyl, phenyl, 3-carboxyphenyl,4-carboxyphenyl, 3,4-dicarboxyphenyl or 3,5-dicarboxyphenyl; and

R¹ and R² are as hereinbefore defined.

In the compound of Formula (2) it is preferred that R¹ is NH₂ or--NH--C₁₋₄ -alkyl, especially methylamino or ethylamino; and R² is H,C₁₋₄ -alkyl, especially methyl or C₁₋₄ -alkoxy, especially methoxy;halo, especially chloro; or sulpho. It is especially preferred that R¹is NH₂ and R² is C₁₋₄ -alkoxy, especially methoxy.

The compound of Formula (1) may be in the free acid form, as shown, butis preferably in the form of a salt with a cation such as an alkalimetal, ammonium or optionally substituted C₁₋₄ -alkyl-ammonium cation ora mixture of such cations. The preferred C₁₋₄ -alkyl-ammonium cationconsists of a nitrogen atom having up to four substituents selected fromC₁₋₄ -alkyl and hydroxy-C₁₋₄ -alkyl, for example mono-, di-,tri- andtetra-(C₁₋₄ -alkyl)-ammonium and mono-, di-, tri- andtetra-(hydroxy-C₁₋₄ -alkyl) ammonium. It is, however, especiallypreferred that the cation is ammonium (i.e. NH₄ ⁺), methylammonium,dimethylammonium or triethylammonium or that the dye of Formula (1) isin the form of a mixed salt with alkali metal (especially lithium orsodium), and ammonium cations.

Examples of optionally substituted C₁₋₄ -alkylammonium cations includemethylammonium, ethylammonium, dimethylammonium, diethyl-ammonium,trimethylammonium, triethylammonium, tri- (2-hydroxyethyl)-ammonium andtetramethylammonium.

The present compounds can be prepared by diazotising an amine of formulaA--NH₂, preferably below 5° C. using a nitrite and mineral acid,coupling with a substituted aniline carrying R¹ and R² to give a monoazocompound, diazotising the resultant monoazo compound and coupling with acompound of Formula (3): ##STR4##

Compounds of Formula (3) in which B and R³ are other than H, may beprepared using the Bucherer reaction in whichl-hydroxy-3-sulpho-7-hydroxy (or 7-amino)-naphthalene or1-hydroxy-3,6-disulpho-7-hydroxy (or 7-amino)-naphthalene is reactedwith an amine, R³ NHB, in the presence of an alkali metal or ammoniumsulphite and bisulphite (e.g. Na₂ SO₃ and NaHSO₃) with heating,preferably from 60°-100° C. and especially 70°-90° C. In these processesA, R¹, R², R³, T and B are as hereinbefore defined.

The present invention relates not only to a compound of Formula (1), butalso to a composition comprising two or more compounds of Formula (1).An example of such a composition is a mixture containing two compoundsof Formula (1) in which T, R¹, R² and R³ are identical in both compoundsbut the identities of A and/or B differ.

It is preferred that such a composition contains two compounds ofFormula (1) in a weight ratio of 99:1 to 1:99, more preferably 90:10 to10:90, especially 80:20 to 20:80, more especially 60:40 to 40:60.

The compound or composition of the present invention can be convertedinto its ammonium or optionally substituted lower alkyl-ammonium salt bydissolving the compound in the form of a salt with an alkali metal,acidifying with a mineral acid, e.g. HCl, adjusting the solution to pH9-9.5 with ammonia or an optionally substituted lower alkylamine andremoving alkali metal and chloride ions by dialysis.

It will be understood that the present invention covers all tautomericforms of a compound of Formula (1), e.g. the tautomeric equivalent ofFormula (1) in which the hydroxy group on the Gamma acid moiety is inthe keto form.

A compound or composition of the present invention, particularly in theform of its ammonium or optionally substituted lower alkylammonium salt,is a useful colorant for an ink. It exhibits high solubility in waterand aqueous media and good water fastness and gives a print with astrong black shade on plain paper. Compounds wherein R¹ is NH₂ ormethylamino and R² is H, alkyl, especially methyl or alkoxy, especiallymethoxy, perform particularly well. Especially preferred are compoundsin which R¹ is NH₂ and R² is methoxy as these give images on plain paperwith an intense neutral black shade, i.e. the a* and b* values in theCIEL*a*b* Color System are close to zero. The compound and compositionare versatile, exhibiting high water fastness on alkaline, neutral andacid papers, good solubility in aqueous ink media, minimal bronzing andgive strong neutral black images.

A suitable ink comprises a compound or a composition according to thepresent invention and a liquid medium, preferably an aqueous medium. Itis preferred that the compound or composition is completely dissolved inthe liquid medium to form a solution.

The ink preferably contains from 0.5% to 20%, more preferably from 0.5%to 15%, and especially from 1% to 3%, by weight of the compound orcomposition, based on the total weight of the ink. Although many inkscontain less than 5% by weight of colorant, it is desirable that thecompound or composition has a water solubility of around 10% or more toallow the preparation of concentrates from which more dilute inks can beprepared and to minimise the chance of precipitation of colorant ifevaporation of solvent occurs during use of the ink.

The liquid medium is preferably water or a mixture comprising water anda water-soluble organic solvent, preferably in a weight ratio from 99:1to 1:99, more preferably from 95:1 to 50:50 and especially from 90:10 to60:40.

The water-soluble organic solvent is preferably a C₁₋₄ -alkanol such asmethanol, ethanol, n-propanol, i-propanol, n-butanol, s-butanol,t-butanol or i-butanol; an amide such as dimethylformamide ordimethylacetamide; a ketone or ketone alcohol such as acetone ordiacetone alcohol; an ether such as tetrahydrofuran or dioxane; anoligo- or poly-(alkylene glycol) such as diethylene glycol, triethyleneglycol, polyethylene glycol or polypropylene glycol; an alkylene glycolor thioglycol containing a C₂ -C₆ -alkylene group such as ethyleneglycol, propylene glycol, butylene glycol, pentylene glycol or hexyleneglycol and thiodiglycol; a polyol such as glycerol or 1,2,6-hexanetriol;a lower alkyl ether of a polyhydric alcohol such as 2-methoxyethanol,2-(2-methoxyethoxy)ethanol, 2-(2-ethoxyethoxy)-ethanol, 2-2-(2-methoxy-ethoxy)ethoxy!ethanol, 2-2-(2-ethoxyethoxy)-ethoxy!-ethanol; a heterocyclic ketone, such as2-pyrrolidone and N-methyl-2-pyrrolidone; or a mixture containing two ormore of the aforementioned water-soluble organic solvents, for examplethiodiglycol and a second glycol or diethylene glycol and 2-pyrrolidone.

Preferred water-soluble organic solvents are selected from2-pyrrolidone, N-methylpyrrolidone, alkylene glycol and oligo-(alkyleneglycol)s such as ethylene glycol, diethylene glycol, triethylene glycoland lower alkyl ethers of polyhydric alcohols such as or2-methoxy-2-ethoxy-2-ethoxyethanol; and polyethylene glycols with amolecular weight of up to 500. A preferred specific solvent mixture is abinary or ternary mixture of water and/or diethylene glycol and/or,2-pyrrolidone or N-methylpyrrolidone in a weight ratios 75-95:25-5 and60-80:0-20:0-20 respectively.

Examples of suitable ink media are given in U.S. Pat. No. 4,963,189,U.S. Pat. No. 4,703,113, U.S. Pat. No. 4,626,284 and EP 4,251,50A.

A further aspect of the present invention provides a process forprinting a substrate with an ink using an ink jet printer, characterisedin that the ink contains at least one compound according to the firstaspect of the present invention.

A suitable process for the application of an ink as herein- beforedefined comprises forming the ink into small droplets by ejection from areservoir through a small orifice so that the droplets of ink aredirected at a substrate. This process is commonly referred to as ink jetprinting, and the ink jet printing processes for the present inks arepreferably piezoelectric ink jet printing and, more especially, thermalink jet printing. In thermal ink jet printing, programmed pulses of heatare applied to the ink in the reservoir by means of a resistor adjacentto the orifice, during relative movement between the substrate and thereservoir.

A preferred substrate is an overhead projector slide or a cellulosicsubstrate, especially cotton or paper, including plain and treatedpapers, which may have an acid, alkaline or neutral character.

The preferred ink used in the process is as hereinbefore described.

According to a still further aspect of the present invention there isprovided a paper or an overhead projector slide carrying a printed imagecomprising a compound of Formula (1) as defined herein.

The invention is further illustrated by the following Examples in whichall parts and percentages are by weight unless otherwise indicated.

EXAMPLE 1 Preparation of the Compound of Formula (A) ##STR5## Stage 1

To a stirred suspension of 3-aminobenzoic acid (27.4 g) in ice/water(500 ml), HCl (35%, 50 ml) was added, followed by a solution of NaNO₂(15.2 g) in water (100 ml), maintaining the temperature at 0°-10° C. bythe addition of small quantities of ice as necessary. When the additionwas complete the resultant diazo solution was stirred at 0°-10° C. for 1hour and residual HNO₂ destroyed by the addition of sulphamic acid.3-Amino-4-methoxyacetanilide (40 g) was dissolved in methylated spirits(74% OP, 500 ml) and added to the above diazo solution at 0°-10° C. andthe mixture was stirred for 18 hours, allowing the temperature to riseto 20° C. The precipitated product was filtered off and the filter cakewashed with water (2000 ml) and dried at 60° C.

Stage 2

The product of Stage 1 (19.7 g) was dissolved in water (500 ml) at roomtemperature by adding NaOH liquor to raise the pH to 10-11. A solutionof NaNO₂ (4.5 g) in water (50 ml) then added. The resulting solution wasadded to a mixture of HCl (35%, 30 ml) and ice-water (100 ml) over 10minutes, maintaining the temperature at 0°-10° C. After 2 hours at0°-10° C., excess HNO₂ was destroyed by addition of sulphamic acid, togive a diazo solution.

N-(4-carboxyphenyl)Gamma acid (25 g) was dissolved in water (400 ml) byadding NaOH liquor to pH 9.0 and the solution was cooled to 0°-10° C.The diazo solution was added slowly over 10 minutes to the solution ofN-(4-carboxyphenyl)Gamma acid, maintaining the pH at 8-9 by addition of2N NaOH solution. The mixture was then heated to 50°-60° C. and saltedwith 7% NaCl. The precipitated product of Formula (A) (mainly Na salt)was filtered and washed with 10% NaCl solution.

Stage 3

A portion of the intermediate product from Stage 2 (as Na+salt, 20 g)was heated in a mixture of 2N NaOH (600 ml) and methylated spirits (740CP, 400 ml) at 65°-70° C. for 2 hours. The solution was cooled, adjustedto pH 6 with 35% HCl and the precipitated product of Formula (A) wasfiltered off and washed with 10% NaCl solution.

Stage 4

The product from Stage 3 was dissolved in water (1.51) by addition ofconcentrated NH₄ OH to pH 9-9.5. This solution was added to 1N HCl (1000ml) and the product of Formula (A) (free acid) was filtered and washedwith 1N HCl. The dissolution and re-precipitation procedure was repeatedand the resultant paste was added to water (51) and the pH adjusted to9.0 with concentrated NHOH. The resulting solution was dialysed untilCl⁻ could no longer be detected, screened through a 0.45 μm filter, andthe product of Formula (A) (NH₄ ⁺ salt) isolated by evaporation.

Evaluation

The aqueous solubility of the ammonium salt of the compound of Formula(A) is >10%. A portion of this salt (2.5 parts) was dissolved in amixture of water (90 parts) and diethylene glycol (10 parts) and thesolution printed onto plain paper using a thermal ink jet printer. Theimage had a strong, neutral black shade with high water fastness.

EXAMPLE 2 Preparation of the compound of Formula (B) ##STR6##

The procedure of Example 1 was repeated except that in place of the3-carboxybenzoic acid used in Stage 1 there was used the same amount of4-carboxybenzoic acid to produce the product of Formula (B) (as NH₄ ⁺salt).

Evaluation

The aqueous solubility of the NH₄ ⁺ salt of the compound of Formula (B)is >10%. When this salt was made into an ink and applied to plain paperby ink jet printing, as described in the Evaluation stage of Example 1,the intense neutral black image had a high optical density and very highwater-fastness.

EXAMPLE 3 Preparation of the compound of Example (C) ##STR7##

The method of Example 1 was repeated except that in place of3-aminobenzoic acid used in Stage 1 there was used the same amount of4-aminobenzoic acid and in place of the N-(4-carboxyphenyl)Gamma acidused in Stage 2 there was used the same amount ofN-(3-carboxyphenyl)-Gamma acid to produce the compound of Formula (C)(as NH₄ salt).

Evaluation

The NH₄ ⁺ salt of the compound of Formula (C) has an aqueoussolubility >10%. When this salt was made into an ink and applied toplain paper by ink jet printing, as described in the Evaluation stage ofExample 1, the intense neutral black image had a high optical densityand very high water-fastness.

EXAMPLE 4 Preparation of the compound of Formula (D) ##STR8##

The procedure of Example 1 was repeated except that in place of the3-amino-4-methoxyacetanilide used in Stage 1 there was used anequivalent amount of 3-aminoacetanilide to give the product of Formula(D).

Evaluation

The aqueous solubility of the NH₄ ⁺ salt of the compound of Formula (D)is >10%. When a portion of this salt was made into an ink and applied toplain paper by ink jet printing, as described in the Evaluation stage ofExample 1, the intense neutral black image had a high optical densityand very high water fastness.

EXAMPLE 5 Preparation of the compound of Formula (E) ##STR9##

The method of Example 1 was repeated except that in place of the3-aminobenzoic acid and 3-amino-4-methoxyacetanilide used in Stage 1there were used equivalent amount of 4-aminobenzoic acid and3-amino-acetanilide and in place of the N-(4-carboxyphenyl)Gamma acidused in Stage 2 there was used the same amount ofN-(3-carboxyphenyl)-Gamma acid to produce the compound of Formula (E)(as NH₄ ⁺ salt).

Evaluation

The aqueous solubility of the ammonium salt of the compound of Formula(E) is >10%. When this salt was made into an ink and applied to plainpaper, as described in Example 1, the image had a high optical densityand very high water-fastness.

EXAMPLE 6 Preparation of the compound of Formula (F) ##STR10##

The method of Example 1 was repeated except that in place of the3-carboxybenzoic acid used in Stage 1 there was used an equivalentamount of 3,5-dicarboxybenzoic acid to produce the compound of Formula(F) as ammonium salt.

Evaluation

The aqueous solubility of the ammonium salt of the compound of Formula(F) is >10%. When this salt was made into an ink and applied to plainpaper by ink jet printing, as described in Example 1, the image hadsimilar properties to that of the image from the ink containing thecompound of Formula (A).

EXAMPLE 7 Preparation of compound of Formula (G) ##STR11##

The procedure of Example 1 was repeated except that in place of the3-aminobenzoic acid used in Stage 1 there was used an equivalent amountof 5-aminoisophthalic acid and in place of theN-(4-carboxy-phenyl)-Gamma acid used in Stage 2 there was used anequivalent amount of N-phenyl-Gamma acid to produce the compound ofFormula (G) as ammonium salt.

Evaluation

The aqueous solubility of the ammonium salt of the compound of Formula(G) is about 9%. When this salt was made into an ink and applied toplain paper by ink jet printing, as described in Example 1, the imagehad a high optical density and very high water-fastness.

EXAMPLE 8 Preparation of the Compound of Formula (H) ##STR12## Stage 1

To a stirred suspension of 3-aminobenzoic acid (13.7 g, 0.1M) inice/water (150 ml), HCl (35%, 30 ml) was added, followed by a solutionof NaNO₂ (7 g) in water (50 ml), maintaining the temperature at 0°-10°C. by the addition of small quantities of ice as necessary. When theaddition was complete the resultant diazo solution was stirred at 0°-10°C. for 1 hour and residual HNO₂ destroyed by the addition of sulphamicacid (10% solution).

3-Amino-4-methoxyacetanilide (20 g, 0.1M) was dissolved in methylatedspirits (74% OP, 500 ml) and added to the above diazo solution. Themixture was stirred for 18 hours at 20°-25° C. The precipitated productwas filtered off and the filter cake washed with water (500 ml).

Stage 2

The paste from Stage 1 was dissolved in water (500 ml) at roomtemperature by adding 2N NaOH to pH 9. NaNO₂ solution (7 g) in water (50ml) was added and the reaction mixture acidified by adding to a mixtureof HCl (35%, 30 ml) and ice-water (150 ml) over 10 minutes, maintainingthe temperature at 0°-10° C. After 2 hours at 0°-10° C. the excess HNO₂was destroyed by adding sulphamic acid, to give a diazo solution.

An aqueous solution of Gamma acid was prepared by adding Gamma acid(26.5 g, 0.1M) to water (400 ml) followed by 2N NaOH to pH 9.0 and Na₂CO₃ (log). The resulting solution was cooled to 0°-10° C. and the diazosolution was added slowly over 10 minutes, maintaining the pH at 9-10 byaddition of 2N NaOH, and then stirred for 1 hour at 0°-10° C.

Stage 3

The solution from Stage 2 was mixed with NaOH liquor (47%, 300 ml) andmethylated spirits (74% OP, 1000 ml) and heated to 70°-80° C. for 4hours (to hydrolyse the acetamido group to free amine) and adjusted topH 7.0 by the addition of HCl. The precipitated compound of Formula (H)(free acid) was collected by filtration and washed with water.

Stage 4

The paste from Stage 3 was dissolved in water (500 ml) and slowly addedto 1N HCl (1000 ml) and the compound of Formula (H) (free acid) wasfiltered and washed with 1N HCl. The isolated paste was added to water(500 ml) and the pH adjusted to 9.0-9.5 with concentrated NH₄ OHsolution. The resulting solution was dialysed until Cl⁻ ion could nolonger be detected, screened through a 0.45 μm filter, water evaporatedoff and the solid dried.

The aqueous solubility of the ammonium salt of the compound of Formula(H) is about 9%. This salt (2.5 parts) was added to a mixture of water(90 parts) and 2-pyrrolidone (10 parts) and printed onto plain paperusing a thermal ink jet printer. The print had a strong black shade withhigh water fastness (97%), no visible bronzing and an optical density of1.38. The same salt was dissolved in a mixture of water (90 parts) anddiethylene glycol (10 parts) and printed onto plain paper to give aprint with good light fastness.

EXAMPLE 9 Preparation of the Compound of Formula (J) ##STR13##

The method of Example 8 was repeated except that in place of the3-aminobenzoic acid used in Stage 1 there was used 5-amino-isophthalicacid (18.1 g) to produce the compound of Formula (J) as ammonium salt.

Evaluation

The aqueous solubility of the ammonium salt of the compound of Formula(J) is >10%. A portion of this salt (2.5 parts), was made into inks asdescribed in Example 1 and printed onto plain paper using a thermal inkjet printer. The resultant print had a neutral black shade with veryhigh water-fastness (96%) and high optical density.

EXAMPLE 10 Preparation of the Compound of Formula (K) ##STR14##

The method of Example 8 was followed except that in place of the Gammaacid used in Stage 2 there was used N-methyl-Gamma acid (20 g) toproduce the compound of Formula (K) as ammonium salt.

Evaluation

The aqueous solubility of the ammonium salt of the compound of Formula(K) is about 8%. This salt was converted into inks and printed ontoplain paper as described in Example 8. The resulting prints had a veryhigh resistance to water (97%) and neutral black shades.

EXAMPLE 11 Preparation of the compound of Formula (L) ##STR15##

The procedure of Example 1 was repeated except that in place of the3-aminobenzoic acid and the 3-amino-4-methoxyacetanilide used in Stage 1there were used equivalent amounts of 5-aminoisophthalic acid and3-amino-4-sulphoacetanilide respectively and in place of theN-(4-carboxyphenyl)-Gamma acid used in Stage 2 there was used anequivalent amount of N-phenyl-Gamma acid to produce the compound ofFormula (L) as ammonium salt.

Evaluation

The aqueous solubility of the ammonium salt of the compound of Formula(L) is >10%. When this salt was made into an ink and applied to plainpaper by ink jet printing, as described in the Evaluation stage ofExample 1, the image had a high optical density and very highwater-fastness.

EXAMPLE 12 Preparation of the compound of Formula (M) ##STR16##

The procedure of Example 8 was repeated except that in place of the3-aminobenzoic acid used in Stage 1 there was used an equivalent amountof 5-aminoisophthalic acid and in place of the Gamma acid used in Stage2 there was used an equivalent amount of N-(piperid-4-ylmethyl)-Gammaacid to produce the compound of Formula (M) as ammonium salt.

Evaluation

The aqueous solubility of the ammonium salt of the compound of Formula(M) is about 6%. When this salt was made into an ink and applied toplain paper by ink jet printing, as described in the Evaluation stage ofExample 1, the image had a high optical density and very highwater-fastness.

EXAMPLE 13 Preparation of the compound of Formula (N) ##STR17##

The procedure of Example 8 was repeated except that in place of the3-aminobenzoic acid used in Stage 1 there was used an equivalent amountof 5-aminoisophthalic acid and in place of the Gamma acid used in Stage2 there was used an equivalent amount of N-(2-aminoethyl)-Gamma acid toproduce the compound of Formula (N) as ammonium salt.

Evaluation

The aqueous solubility of the ammonium salt of the compound of Formula(N) is >10%. When this salt was made into an ink and applied to plainpaper by ink jet printing, as described in the Evaluation stage ofExample 1, the image had a high optical density and very highwater-fastness.

EXAMPLE 14

Further inks may be prepared having the compositions described in Tables1 and 2 below wherein Inks 1-5 contain the compound of Formula (A), Inks6-10 contain the compound of Formula (B), Inks 11-15 contain thecompound of Formula (C), Inks 16-20 contain the compound of Formula (D),Inks 21-25 contain the compound of Formula (E), Inks 26-30 contain thecompound of Formula (G) and Inks 30 to 34 the compound of Formula (H).

                                      TABLE 1                                     __________________________________________________________________________    Ink                                                                              Dye                    Na                                                  No.                                                                              Content                                                                           Water                                                                             PG                                                                              DEG                                                                              NMP                                                                              DMK                                                                              NaOH                                                                              Stearate                                                                          IPA                                                                              MEOH                                                                              DMA                                                                              MIBK                                  __________________________________________________________________________     1 2.0 80  5    6  4                 5                                         2 3.0 90    5  5     0.2                                                      3 1.0 85  5    2  2      0.1    5   1                                         4 2.1 91    8                          1                                      5 3.1 86  5              0.2 4         5                                      6 1.1 81       9     0.5 0.5        9                                         7 2.5 60  4 15 3  3          6  10  5  4                                      8 1.9 70    20               10                                               9 2.4 75  5 4     5             6      5                                     10 4.1 80  3 5  2  10     0.3                                                 11 3.2 65    5  4  6          5  4   6  5                                     12 4.6 96                        4                                            13 0.8 90  5                  5                                               14 1.2 80  2 6  2  5          1      4                                        15 1.8 80    5                       15                                       16 2.6 84       11                   5                                        17 3.3 80  2       10            2      6                                     18 1.7 90          7  0.3     3                                               19 1.5 69  2 20 2  1                 3  3                                     20 1.6 91       4                    5                                        __________________________________________________________________________     Key to abbreviations is at foot of Table 2                               

                                      TABLE 2                                     __________________________________________________________________________    Ink                                                                              Dye                    Na                                                  No.                                                                              Content                                                                           Water                                                                             PG DEG                                                                              NMP                                                                              CET                                                                              TBT                                                                              Stearate                                                                          BDL                                                                              PHO                                                                              2P TDG                                    __________________________________________________________________________    21 3.0 80  15       0.2             5                                         22 2.0 90     5                  1.2   5                                      23 1.5 85  5  5      0.15                                                                            5.0                                                                              0.2                                                 24 2.5 90     6  4                0.12                                        25 3.1 82  4  8     0.3                6                                      26 0.9 85     10              5  0.2                                          27 1.5 90     5  5        0.3                                                 28 2.9 70     10 4            1     4  11                                     29 2.2 75  4  10 3            2     6                                         30 2.6 91        6                  3                                         31 3.2 76     9  7     3.0        0.95                                                                            5                                         32 4.0 78  5  11                    6                                         33 3.3 86        7                  7                                         34 1.1 70  5  5  5  0.1                                                                              0.2                                                                              0.1 5  0.1                                                                              5  5                                      __________________________________________________________________________     The following abbreviations are used in Tables 1 and 2:                       PG = propylene glycol                                                         DEG = diethylene glycol                                                       NMP = Nmethylpyrrolidone                                                      DMK = dimethylketone                                                          IPA = ipropanol                                                               MEOH = methanol                                                               TDG = thiodiglycol                                                            BDL = butane2,3-diol                                                          2P = 2pyrrolidone                                                             MIBK = methyli-butylketone                                                    PHO = Na.HPO.                                                                 DMA = dimethylamine                                                           CET = cetyl ammonium bromide (surfactant)                                

We claim:
 1. A compound of the Formula (1) or a salt thereof: ##STR18##wherein: A is optionally substituted phenyl or optionally substitutednaphthyl;R¹ is NR⁴ R⁵ ; R² is H, halo, --COOH, optionally substitutedalkyl, optionally substituted alkoxy, or optionally substitutedalkylthio; R³, R⁴ & R⁵ are each independently H or optionallysubstituted alkyl; T is H or sulpho; and B is H, optionally substitutedalkyl or optionally substituted phenyl;provided that the compound doesnot contain a piperazinyl group; and provided that the compound has atleast as many carboxy groups as sulpho groups.
 2. A compound accordingto claim 1 wherein A is selected from 3-carboxyphenyl, 4-carboxyphenyl,3,5-dicarboxyphenyl and 3,4-dicarboxy-phenyl.
 3. A compound according toclaim 1 or claim 2 wherein R¹ is NH₂ or NH--C₁₋₄ -alkyl.
 4. A compoundaccording to any one of claims 1 to 3 wherein R² is selected from H,methyl, methoxy, chloro, and --COOH.
 5. A compound according to any oneof claims 1 to 4 wherein B is selected from phenyl, 3-carboxyphenyl,4-carboxyphenyl, 3,5-dicarboxy- phenyl, H and methyl.
 6. A compoundselected from the group comprising1-hydroxy-2-2-methoxy-4-(3-carboxyphenylazo)-5-amino-phenylazo!-3-sulpho-7-(4-carboxyphenylamino)-naphthalene;1-hydroxy-2-2-methoxy-4-(4-carboxyphenylazo)-5-amino-phenylazo!-3-sulpho-7-(4-carboxyphenylamino)-naphthalene1-hydroxy-2-2-methoxy-4-(3,5-dicarboxyphenylazo)-5-amino-phenylazo!-3-sulpho-7-(4-carboxyphenylamino)-naphthalene;1-hydroxy-2-2-methoxy-4-(3,5-dicarboxyphenylazo)-5-amino-phenylazo!-3-sulpho-7-amino-naphthalene;1-hydroxy-2-2-methoxy-4-(3-carboxyphenylazo)-5-amino-phenylazol-3-sulpho-7-amino-naphthalene;and 1-hydroxy-2-2-methoxy-4-(3-carboxyphenylazo)-5-amino-phenylazo!-3-sulpho-7-methylamino-naphthalene.7. A compound according to any one of claim 6 in the form of theammonium or substituted ammonium salt.
 8. An ink comprising a compoundaccording to any one of claims 1 to 7 and a liquid medium.
 9. An inkaccording to claim 8 wherein the liquid medium is water or a mixturecomprising water and a water-soluble organic solvent.
 10. A process forprinting a substrate by ink jet printing by applying thereto an inkaccording to claim 8 or claim
 9. 11. A compound according to claim 1which has no more than 2 sulpho groups.
 12. A compound according toclaim 1 which has only a single sulpho group.
 13. A compound accordingto claim 1 which has from 1 to 5 carboxy groups.
 14. A compoundaccording to claim 1 which has 2 or 3 carboxy groups.
 15. An inkcomprising a compound according to any one of claims 11 to 14 and aliquid medium comprising water and a water-soluble organic solvent.